Cypress CY7C1302DV25 manual Application Example1

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CY7C1302DV25

Synchronous internal circuitry will automatically three-state the outputs following the next rising edge of the positive output clock (C). This will allow for a seamless transition between devices without the insertion of wait states in a depth expanded memory.

Write Operations

Write operations are initiated by asserting WPS active at the rising edge of the positive input clock (K). On the same K clock rise the data presented to D[17:0] is latched into the lower 18-bit Write Data register provided BWS[1:0] are both asserted active. On the subsequent rising edge of the negative input clock (K), the address is latched and the information presented to D[17:0] is stored into the Write Data register provided BWS[1:0] are both asserted active. The 36 bits of data are then written into the memory array at the specified location.

When deselected, the Write port will ignore all inputs after the pending Write operations have been completed.

Byte Write Operations

Byte Write operations are supported by the CY7C1302DV25. A Write operation is initiated as described in the Write Operation section above. The bytes that are written are deter- mined by BWS0 and BWS1 which are sampled with each set of 18-bit data word. Asserting the appropriate Byte Write Select input during the data portion of a write will allow the data being presented to be latched and written into the device. Deasserting the Byte Write Select input during the data portion of a write will allow the data stored in the device for that byte to remain unaltered. This feature can be used to simplify Read/Modify/Write operations to a Byte Write operation. 38-05625

Single Clock Mode

The CY7C1302DV25 can be used with a single clock mode. In this mode the device will recognize only the pair of input clocks (K and K) that control both the input and output

registers. This operation is identical to the operation if the device had zero skew between the K/K and C/C clocks. All timing parameters remain the same in this mode. To use this mode of operation, the user must tie C and C HIGH at power-up.This function is a strap option and not alterable during device operation.

Concurrent Transactions

The Read and Write ports on the CY7C1302DV25 operate completely independently of one another. Since each port latches the address inputs on different clock edges, the user can Read or Write to any location, regardless of the trans- action on the other port. Also, reads and writes can be started in the same clock cycle. If the ports access the same location at the same time, the SRAM will deliver the most recent infor- mation associated with the specified address location. This includes forwarding data from a Write cycle that was initiated on the previous K clock rise.

Depth Expansion

The CY7C1302DV25 has a Port Select input for each port. This allows for easy depth expansion. Both Port Selects are sampled on the rising edge of the Positive Input Clock only (K). Each port select input can deselect the specified port. Deselecting a port will not affect the other port. All pending transactions (Read and Write) will be completed prior to the device being deselected.

Programmable Impedance

An external resistor, RQ, must be connected between the ZQ pin on the SRAM and VSS to allow the SRAM to adjust its output driver impedance. The value of RQ must be 5X the value of the intended line impedance driven by the SRAM, The allowable range of RQ to guarantee impedance matching with a tolerance of ±15% is between 175Ω and 350Ω, with VDDQ =1.5V. The output impedance is adjusted every 1024 cycles to account for drifts in supply voltage and temperature.

Application Example[1]

Note:

1. The above application shows 4 QDR-I being used.

Document #: 38-05625 Rev. *A

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Contents Features ConfigurationsLogic Block Diagram CY7C1302DV25 Functional DescriptionSelection Guide Pin Configuration Ball Fbga 13 x 15 x 1.4 mm PinoutPin Definitions Introduction Application Example1 Operation Write Cycle Descriptions 2,8Comments Ieee 1149.1 Serial Boundary Scan Jtag Sample Z TAP Controller State Diagram9 EXIT2-IR UPDATE-DR UPDATE-IRTAP Controller Block Diagram Parameter Description Test Conditions Min Max UnitParameter Description Min Max Unit Set-up TimesTAP Timing and Test Conditions12 Identification Register DefinitionsScan Register Sizes Instruction CodesRegister Name Bit Size Instruction Code DescriptionBoundary Scan Order Bit # Bump IDRange Ambient Temperature T Maximum RatingsOperating Range Parameter Description Test Conditions Min Typ Max UnitSwitching Characteristics Over the Operating Range Thermal Resistance20Capacitance20 AC Test Loads and WaveformsSwitching Characteristics Over the Operating Range Clock Rise or K/K in single clock mode to Data ValidClock Rise Active to Active Rise to High-Z Active to High-Z 23Switching Waveforms25, 26 Write Read NOPPackage Diagram Ordering InformationCY7C1302DV25-167BZXC CY7C1302DV25-167BZXIIssue Date Orig. Description of Change Document History

CY7C1302DV25 specifications

The Cypress CY7C1302DV25 is a high-performance static random-access memory (SRAM) device designed to meet the demanding requirements of modern electronic systems. It operates with a supply voltage of 2.5V, making it ideal for battery-powered applications, while offering up to 1 Mbit of memory storage. This device is widely used in various applications, including telecommunications, networking, and industrial automation, due to its speed, reliability, and efficiency.

One of the main features of the CY7C1302DV25 is its fast access time, which reaches as low as 10 nanoseconds. This rapid access allows for quicker data retrieval and processing, enhancing overall system performance. The device supports asynchronous read and write operations, providing flexibility in how data is managed and utilized within a system.

The CY7C1302DV25 has a rich set of functionalities that include word and byte write modes, allowing for efficient data manipulation. Its dual-port architecture enables simultaneous read and write operations, making it suitable for applications requiring high data throughput. This feature is particularly beneficial in systems where multiple devices need to access or update memory concurrently.

From a technological standpoint, the CY7C1302DV25 utilizes advanced CMOS technology, which not only contributes to its low power consumption but also enhances its durability and reliability. Lower power consumption is a crucial aspect for many applications, especially in portable devices, where battery life is a significant concern. The CY7C1302DV25 also incorporates built-in write protection, ensuring data integrity and security against unintentional writes during operation.

In terms of physical characteristics, the device comes in a compact 44-pin Thin Quad Flat No-lead (TQFN) package, making it suitable for space-constrained designs. Its small footprint allows for integration into densely packed circuit boards, providing manufacturers with flexibility in design.

Overall, the Cypress CY7C1302DV25 is a versatile and efficient SRAM solution that combines speed, low power consumption, and robust features, making it an excellent choice for a wide range of applications in the ever-evolving landscape of electronics. Its reliability and advanced specifications position it as a dependable memory solution for both current and future technologies.
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